exhaust backfire

Information and questions on GL1100 Goldwings (1980-1983)
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Joined: Sat Jul 09, 2011 10:33 am
Location: Stanton,Michigan
Motorcycle: 1980 gl1100 Interstate
1977 gl1000

exhaust backfire

Post by blackbeauty » Mon May 26, 2014 9:55 am

I have an 80 wing and replaced the stock exhaust with a set of fishtail pipes over the winter, I am getting a pop while riding and also on slowing down. The bike is getting about 38 miles to the gallon and runs ok. It does have a fall on its face at above 5500 rpm, but just cruising it does good. I synced the carbs this spring. Am I looking at timing issues. What if any problems can come from this.


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Re: exhaust backfire

Post by Sidcar » Mon May 26, 2014 2:30 pm

Check for an air leak on your exhaust. Any air drawn in through the leak on overrun will cause popping back in the exhaust.


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Re: exhaust backfire

Post by themainviking » Mon May 26, 2014 2:53 pm

Also, you may have created a lean condition with the fishtails if they have no baffles in them, which could cause the popping you are experiencing on decelaration. Installing baffles in the fishtails could eliminate your problem, although definitely check for a vacuum leak as mentioned above.
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Re: exhaust backfire

Post by dingdong » Tue May 27, 2014 6:11 am

Another possibility: Your carbs have "air cutoff valves" that are designed to eliminate backfire on deceleration. One or more could be bad.

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Re: exhaust backfire

Post by Bogator » Sun Jun 01, 2014 6:09 am

OK, this is what I found on my Valkyrie, vacuum lines --rotten---I replaced all ,and then I tightened all header bolts, be careful with these and don't over tighten, you might find another problem with the wiring but ---try --the first of these and then see hope this helps GOD BLESS


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